This study evaluated whether psychiatric comorbidity is related to change i
n HIV high risk behaviors during outpatient drug abuse treatment. Participa
nts were opioid abusers entering methadone treatment. Psychiatric and subst
ance use diagnoses were determined at intake. Information on HIV high risk
drug use and sexual behaviors, psychosocial functioning, and urine toxicolo
gy was assessed at intake and at month six. Subjects were divided into thos
e with versus without a lifetime comorbid non-substance use psychiatric dis
order. The comorbid group reported more injection equipment sharing, lower
rates of condom use, and higher rates of alcohol use at intake and follow-u
p. Overall injection drug use behavior decreased over the follow-up period
for both groups, however. Methadone treatment had a beneficial effect on HI
V risk behaviors, and though some risk behaviors improved significantly for
both groups, comorbid subjects continued to have higher rates of HIV risk
factors than noncomorbid subjects.